Gliftex can output .EPS and
.PS vector files ideal for textile printing. The "vector" part
of that phrase means that the designs have infinite resolution.
You may not see it on a textile printer because the printer has its own
limitations (dots per inch) and so does the textile (the weave, quality
and roughness of the material).

What does vector infinite resolution
mean? It means that no matter how much you zoom into the image you will
never get pixelation or blurriness.

I use Ghostview
a free PS and EPS viewer to look at Gliftex PS and EPS output.

Here is an example:

With Ghostview you can zoom
into the image using the + icon in the toolbar. Let's zoom in a bit:

We can really zoom in a lot
and see that there is no pixellation:

If, when you print your Gliftex
design (saved as EPS or PS), you see pixellation or blurriness there is
a problem with the printer, its driver or the textile.

The PRO version of Gliftex
has vector output and costs $24.99. There
is a free demo so you can experiment
yourself with creating designs and printing them.